Various silica glass devices and articles have become of intense interest in recent years for a variety of reasons generally associated with the development of optical devices and the development of optical communication systems. Particularly important has been the development of various processes for producing silica-glass devices of high quality for use in optical devices and optical communication devices.
Much attention and effort has been applied to the manufacture of optical fibers for use in optical communication systems. Here, exact standards are required to insure low-loss and low-distortion transmission of optical signals down the optical fiber so as to achieve maximum bandwidth and maximum distance between repeater stations. Often in the manufacture of optical devices involving optical glasses (including optical fibers) various shaping operations involving etching are required.
A particularly difficult problem involves coupling radiation in and out of the ends of the optical fibers. This often involves shaping a lens type structure at the end of the fiber to increase the coupling of light between device (e.g., source or detector) and optical fiber. For example, with an optical source such as a laser, increased efficiency is obtained by shaping a small lens at the end of the optical fiber to increase the coupling of laser radiation into the optical fiber. This often requires first fabricating a point with a particular taper on the end of the fiber and then making the lens usually by a melting procedure. A reliable procedure for reproducibly making a point with a given taper at the end of an optical fiber is highly desirable.